Hierarchical - Main Line Tree layout algorithm properties

When the Hierarchical - Main Line Tree schematic layout algorithm is chosen in the Layout Task drop-down list, clicking the Layout Algorithm Properties button Layout Algorithm Properties icon on the Schematic Editor toolbar opens its associated properties dialog box as follows:

Schematic Layout Algorithm dialog box with Hierarchical - Main Line Tree properties tab

The parameter values are those either specified by default by Schematics or specifically set as the default for the schematic diagram template related to the active diagram using the Schematic Dataset Editor Layouts tab for this schematic diagram template.

About root and end schematic nodes

Root and end schematic nodes can be specified in the diagram so the Hierarchical - Main Line Tree layout algorithm works from a main line starting at the specified root node and ending at the specified end node. Use the Set Schematic Root Set Schematic Root icon and Set Schematic End Set Schematic End icon tools to specify the schematic nodes you want to be considered as the root and end nodes for your diagram.

If your schematic diagram is composed of several disconnected network parts, you might want to define several root and end nodes, for example, one for each part of the network. To define multiple schematic root and end nodes, click the Set Schematic Root or Set Schematic End tool, hold down the SHIFT key, then click the desired nodes.

NoteNote:

  • Several feature nodes that belong to the same connected network part can also be specified as roots. They are all aligned along the same axis and appear as different start points for a branch of the network. For end nodes, although nothing prevents users from specifying several schematic ends on the same connected network part, Schematics considers only one of them the end node.
  • If an end node is specified but no root schematic node is specified, the end node is ignored.
  • In any case, the detected main line is centrally placed with its related branches positioned on either its left or right side or both sides, according to the Branch Placement option that is specified.

Direction options

The Direction options determine the direction of the main line.

Main Line Tree - Directions

Link display parameters

The Link display parameters specify the positioning of vertices that will be added along the schematic links.

Branch Placement options

The Branch Placement options determine how the main line branches are placed.

Figures 3.1 to 3.3 below show the Main Line layout algorithm results for each of the available Branch Placement options.

Main Line Tree—Branch Placement options

Spacing parameters

The Spacing parameters determine how the spacing between the hierarchical levels and the schematic nodes belonging to a given hierarchical level will be computed. The unit for these spacing parameters depends on the Absolute units check box.

Absolute units check box

By default, the Spacing parameters are interpreted as absolute units determined by the coordinate system specified on the XY Coordinate System tab of the Schematic Diagram Properties dialog box (Absolute units checked). Uncheck the Absolute units check box if you want these parameter values to be interpreted as units relative to the average of the current symbol sizes used to represent the schematic nodes in the diagram. In this case, when the Between nodes along the direction parameter value is 2, the distance that separates two schematic nodes belonging to the (n) and the (n+1) hierarchical levels corresponds to the average size of two symbols placed side by side.

NoteNote:

Specifying parameters in relative units is easier than in absolute units but has real meaning only when there is a reference scale for the diagram.

Restore Defaults button

Click the Restore Defaults button to reinitialize all the Main Line Tree parameters with their default values. The restored values are those either specified by default by Schematics or specifically set as the default for the schematic diagram template related to the active diagram using the Schematic Dataset Editor Layouts tab for this schematic diagram template.

Related Topics

2/10/2012